Self-aligning bearing



July 9, 1929. v, J. oBRlEN SELF ALIGNING BEARING Filed July l1. 1927 Patented July 9, 1929.

UITED STATES VINCENT J'. OBRIEN, 0F DENVER, COLORADO.

SELF-ALIGNING- BEARING.

Application filed July 11, 1927. Serial No.A 204,671.

This invention relates to a. self-aligning hearing and, while it more particularly apv plicahle to the joint between the connecting rod and the wrist pin in an internal combustion engine, it will iind many other valuable applications. At present the wrist pins are ground to a close lit with the piston and connect-ing rod hearings. This: accu `ate machining does not allow any play to accommodate inisalignmcnt between the cylinders and cra-uli shaft axis so that strains are occasioned in the connecting rods and the cylin ders are worn unevenly and out oit round.

It is practically impossible to constructan engine with the cylinders at an exact 9Go with the crank shatt axis, and should such a thing he possible, this alignment could not he preserved throughout the lite of the engine owing to uneven wear on the crank shaft hearings and uneven scraping and replacement ot worn hearings. The principal object ot this invention is to provide a joint or connection hetween the connecting rod and the wrist pin et the piston which will accommodate the above mentioned inaccuracies in the engine and which will allow 'the piston to travel evenly throughout the length ot the cylinder regardless oi `any lack of parallelism between the wrist pin and the crank shaft. 1

Another object ot the invention is to incorporate the advantages oi" the first object into an engine withoi'ltit being necessary to increase the reciprocating weight therein.

A. turther object is to provide a connection which will accommodate misalignment of pistons; without allowing rotation thereof within the cylinder.

@ther ehjects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy and eiii ciency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views o't the drawing and throughout the description.

In the drawing:

Fig. 1 is a vertical section through a typii cal internal combustion engine cylinder, taken on the line 1 1, Fig. `2. j

Fig. 2 is a similar view taken on the line @m2, Fig. 1.,

.Fig-8 is an edge elevation ot' the wrist pin extremity of the connecting rod.

Fig. i illustrates the wrist pin with my novel hushinginv place thereon.

Fig. is an end view ci the bushing.

Fig. (i is a diagrammatic view .illustrating astep in the process ot' n'ianu'tacture oi' the connecting rod employed in my invention.

At 10 is illustrated a typical internal coin-- hustion engine piston having the usual wrist pin 11. In the wrist pin 11 I iorm a peripheral, round-hottonied groove il, in which a hall 13 is held hy means ot a set screw 1.4L locked in place hy a lock nut 15; The set screw 14; is adjusted so that the hall 13 will project into the groove 12 without i'riction, hut sufficiently far to prevent endwise niovenient ot the wrist pin 11. however, tree to rotate within the piston l0.

A bushing 16 of bronze, or similar hearing metal, surrounds the wrist pin 11 and is accurately iitted thereon. The bushing 1G is ot unusual construction and is provided with two plane sides 17, a convexly curvated bottom 18 and a concavely curvated top 19..

The convexity and concavity oit the bottom and top extend longitudinally oi? the hushing about a common axis, that is, in side elevation, as in Fig. 4r, the bushing presents a portion of an arc. In cross section, hoth. the bottom and top of the bushing are convenly curved upon a common radius as illustra ed in Figs. 1 and 5. At 2O is illust fated a connecting rod having a head 21, the interior of which is formed similarly to the exterior ot the bushing 16. This head is split at one side as shown at 22, the sides ot the split being held together hy means of a bolt 23. A separator 2d surrounds the holt and maintains the split 22 at the proper separation to allow the head 21 to ride freely on the bushing 1G without play. j

With this construction the ordinary crank movement of the engine causes the bushing to ride on the wrist pin 11. The wrist pin 11, however, is tree to also ride within the piston 10 so that a tree, unobstructed motion is obtained. In addition to this, the piston may rock in an are parallel to the axis et the Wrist pin, or similarly, the connecting rod 2O may rock in this arc to accommodate the inaccuracies in alignment in the engine. This rocking causes the head 21 to slide upon the arcuate bottom and top 1S rThe wrist pin, 4

e as to allow freedom of movement roer Vbottoni Athan et the top. V'lherefore ed and 19V of the bushing han the adjustment of the bolt kand separator E23 and 2l bein.

It has been found impractical to einploy a bell or similar joint between :i conncclng; rod and piston since it allows the piston to rotate. This rotation causes a boring action on the cylinder and also,` in some types of inotors. causes the extremities of tue piston rings to become caught in cylineer'ports. In this invention this objection is VvoirLY since the plane feces 17 prevent horizontal rotation of the bushingv wish-inthe coniuciing redhead 2l. The heedis provided at one side with an inter al similar plane. fece adapted to engage' one of the feces l?, und at the other side with the separat-or 242 which contacts with the lother of the plone farces l?.

Anywvear which may occur be'tween'l'he bushing` "and the heed 2l may be eat 1"-, teken up by grindingl a. portion ofi' the lengthof the separator 24C so il l; the hee:`l maybe drawn further closed. l; saoul-fil notl be closed tight enough, 'liov-ever, to tightly clanipthe bushinff.r

Y Inv a. structure siinilarto 'the one discioelz the greatest pressure end weer between 'the f wrist pin and bushing occurs the l ottoni thereof.

On the explosion stroke, the wrist pin is pressing downwardly on the Vconnecting rochond on the compression stroke, the connectingrod is pressing upwardly on wrist pin so the4 the pressure et ell times onthe bottoni of the wrist 'pin and on the bottoni ofthe wrist pin bushing. It desired to cell attention *to the fact that in nry inventionthis pressure end weer e per'iculerly accommodated since, owi downwardly bowed, arcuateconstruction of the bushing` 16,'its thickness is grenier et *he di tional bearing metal is provided at Vthe poiioV of greatest wenn It is :ilso'vdesired to call altention lo the fact that the bushing 1G und the head 2l need .notJ occupy any greater space nor be of any greater weight than 'the present connecting rod heads and bushings. At its upper edges the bushing' is thicker than the y so 'i usuel` bushing but thisgis compensated for by the feet that it is much thinner et its inner upper portion. This sanie compensation 'true the bottoni where the thickened inner port-ion is compensated for by the thinner edge portion. Y Y Y e The manufacture of the ,bushing 1G for no unusual expenditures. A method of manufacturing the connecting rod heed 2l is indicated in 6, iii-which rorlry drill table is outlined et2`5fupon which e, connecting' rod 120 (or e; series of connecting` rods) is clamped et 26 in the'usuel manner. with its split 22 upwardly. A'Auol'ery niill is spaced away' from the center of the table 25 a distance equal `to the 'radius of the ero necessary to sccfunniodale the urcuae faces of 'the bushing This mill is fixed in ihis position with its stein QT pa sin; through the split Q2 in the connecting rod. 'lhc si inultzineous rotation of die niill and table will now forni the inlerior surface-w ol the head 2l to accurately receive the bushing 1.6.

Vllhis invention designed as :in iinjni'ivcnient upon applicants lacnt No. ldlhlll. i,-sued August 167 i927.

lllhile a specilic forni of the inijuoveincut s been described and illustrated horeln, it desired to be understood that the .saine niay be *uried, vvilhin the scope of the appended claiins, without departing` from the sph-it of the invention.

lflaving thus described the invention, ivhal cle-iin ind desire to secure by Leiters-s lal'- il' is2- l. ln :i bushing` adapted to surround 'llu wrist pin nd receive the connecliunr rod of un internal combustion engine, curvalied upper and lower faces extending` loiunl'udinally of said blushing` comprising porio` s of' orcs about a coinnion axis, said axis being;` positioned beyond the outline of said bushing; and plone side fa joinin` said ourvated feces.

2. ln e, bushing` adapted to surround the wrist pin and receive the connectingrod of an internal combustion engine, curval'cd upper and lower faces extending longitudinelly of said busliinf;` comprising;` portionsl of arcs about o coninion axifa/ said axis heine; positioned beyond the outline of .said liuuhing; and plane side faces joining; sai-d curvzited feces, each of said curval'ed faces also being rounded transversely of .said bushing to :i conunon radius.

it joint between a wrist pin and a councctiugrod coniprisiiuf1 a bushing: adapted to surround said wrist pin; a huigitudinally conczrved surface on the upper sido ol' said bushing; :ly longitudinally convcxcd surface on the lower side of said bushing; and a head on said connecting` rod having' iuternrd surfaces adapted to fit to the surfaces on said bush-ing.

el; A joint between a ivrisl' pin and a connecting rod comprising a bushing` adapted to surround said wrist pin; a longitudinally conceved surface on the upper side of said bushing; a longitudinally convened surface on the lower side of seid busbiiu: plano surfaces on the vertical sides of said bushing; und a head on said connecl'innr rod having linternal surfaces adapted l'olit lo the surfaces on said bushing.

5. fr joint between a wrist pin und a connecting rod comprising` a bushingr adapted to surround seid wrist pin; a longitudinall)7 conceved surface on the upper side of said bushing; longitudinally convened surface. on the lower side of said bushing; a head on seid connecting rod having internal surfaces lll) Ibushing adapted to it to the surfaces on said bush` ing, said head having an open side; means 'foi' preventing the separation of said open side; and othei' means 'for limiting the closing of said open side.

6. A joint between a wrist pin and a connecting i'od comprising a bushing adapted to surround said wrist pin; a loi'igitudiiuilly concaved surface on the upper side o'if said a longitudinally convexed siii-'face on the upper side oi? said bushing; a head on said connecting rod having internal surfaces adapted to fit 'to the surfaces on said hushing, said head having an open side; a holt adapted to span said open side and limit its outward movement; and a. separator suiiounding said bolt and adapt-ed to limit the inner movement of .said open side.

7. A joint between a wrist pin and a connecting rod comprising a bushing adapted to suiiound Said wrist pin; a longitudinally concaved siukzice on the upper side oi said bushing; a longitudinally convened surface on the lowei' side of said bushing, said upper and lowei' surfaces being provided with a transverse curve throughout their length, said curve having a common radius.

8 The combination with a *piston having a wrist pin, of a bushing adapted to suiround said wrist pin7 said bushing having its upper and lower faces longitudinally curved about a common axis, said axis being located below both said uppei' and loweiI faces; and a connecting rod having a socket similai'ly curva-ted so as to receive seid hushing.

in testimony whereof, I ailix my sigi1ature.

VINCENT J. OBRIEN. 

